You can use Custom
Install to
upgrade
vCenter Single Sign-On, vCenter Inventory Service, and vCenter Server
separately to customize the location and configuration of the components.

These instructions upgrade vCenter Inventory
Service only. You must install or upgrade vCenter Single Sign-On before
upgrading Inventory Service and vCenter Server.

Note

vCenter Server 5.5
supports connection between vCenter Server and vCenter Server components by IP
address only if the IP address is IPv4-compliant. To connect to a vCenter
Server system in an IPv6 environment, you must use the fully qualified domain
name (FQDN) or host name of the vCenter Server. The best practice is to use the
FQDN, which works in all cases, instead of the IP address, which can change if
assigned by DHCP.